An oral dose of Fluralaner administered to dogs kills pyrethroid-resistant and susceptible Chagas disease vectors for at least four months.

LAIÑO M; CARDINAL MV; ENRIQUEZ GF; ALVEDRO A; GASPE MS; GÜRTLER RE

VETERINARY PARASITOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 268 p. 98 - 104

0304-4017

New vector control tools that can fit into a broader integrated vector management strategy are notably lacking.We conducted a seven-month randomized trial to assess the efficacy of a single oral dose of Fluralaner(Bravecto®) administered to dogs on the blood-feeding success, engorgement levels and mortality of pyrethroidresistantand -susceptible Triatoma infestans third- and fifth-instar nymphs. The trial included 10 Fluralanertreatedand 10 placebo-treated (control) outbred healthy dogs residing in rural houses of the Argentine Chaco.Most (92.7%) of the 3017 triatomines exposed were able to blood-feed. Generalized linear models showed thatblood-feeding success was not significantly modified by Fluralaner treatment, time posttreatment and theirinteraction. However, pyrethroid-susceptible fifth instars blood-fed significantly more frequently than susceptiblethird instars, and no significant differences were observed between the latter and resistant fifth instars.Engorgement levels were not significantly modified by Fluralaner treatment, time posttreatment and their interaction.Nearly all the triatomines that blood-fed on treated dogs up to 60 days posttreatment (DPT) diedwithin 24 h regardless of pyrethroid susceptibility status combined with bug stage. Cumulative bug mortalityover 4 days postexposure remained high over 90?120 DPT (70?81% in susceptible third and fifth instars, and47?49% in resistant fifth instars), and was virtually nil at 210 DPT. Triatomines that fed on control dogs sufferedmarginal mortality (0?4%) except at 4 and 30 DPT. Fluralaner and xenointoxication are eligible for Phase IIIefficacy trials alone or combined with other methods in the frame of an integrated vector management strategyin areas with or without pyrethroid resistance.